The invention relates to hydraulic shock absorption in punch or cutting presses with at least one damping cylinder which is under preset pressure supplied by a pump with the pressure chamber of the cylinder being connected with a damping valve. When work materials are cut, the pressure of the press builds up to full strength within the first third of the material to be cut. If the material to be cut tears off, then the cutting pressure is suddenly reduced; and in presses without shock absorption, the entire store of energy in the working tools and in the machine frame or stand is liberated virtually without inertia. This results in a very rapid relative movement between the machine base and the ram device and the energy release takes place within a range of milliseconds. Excessively loud noises and increased wear of both press and machine tools thus result.
In order to damp this energy release and flatten the downward curve of the force of the press in order to cushion the accelerated masses, it is known to support the upper portion of the machine against the lower portion by means of hydraulic cylinders. These cylinders have an electronically controlled hydraulic circuit arranged in such a way that when the material to be cut has been entirely cut through, they immmediately take over and slowly drop in pressure over a period of time which is adjustable. A rotary servo valve is provided within the control circuit as the damping valve. The necessity for a complete control circuit including servo valves and subsequent amplifier stages, pressure absorbers, electronic structural parts, switching thresholds and force-actuated diaphragms requires high construction costs and the susceptibility to failure is much greater.